Pneumatic tool



Feb. 22, 1944. R` Q ALLEN l 2,342,568

PNEUMATIC TOO-L Filed Oct. 8, 1942 Hls ATTORNEY.

Patented Feb. 22, 1944 UNITED STATES PNEUMATIC TOOL Roy O. Allen, Athens, Pa., assignor to Ingersoll- Rand Company, Jersey City, N. J., a corporation of New Jersey Application October 8, 1942, Serial No. 461,338

1 Claim.

This invention relates to pneumatic tools and more particularly to an arrangement of parts by which the cap or handle portion is secured to the barrel or cylinder of a hammer type pneumatic tool.

As is generally well known, hammer type pneumatic tools such as chipping hammers, riveters and the like are subject to extremely violent vibration which causes parts which are screwed together to unscrew, regardless of how tightly they may have been set up. For this reason, when parts are threaded together locking means must be employed to prevent relative turning of the threaded parts. In the past, various locking means have been employed but they have been In the attached drawing of a preferred embodi-I ment of the invention and in which similar reference characters refer to similar parts,

Figure 1 is a side view of a portion of a penumatic hammer constructed in accordance with the practice of the invention, a portion of the cap and barrel or cylinder being broken away to show the internal construction, other portions being also in section for the same purpose,

Figure 2 is an external side View of the portion of the pneumatic hammer at and about the joint, showing more particularly the locking means,

Figure 3 is a view of the spring collar for engaging the locking ring to hold the same in place,

Figure 4 is a transverse section taken at 4--4 of Figure 1 looking in the direction of the arrows,

Figure 5 is a transverse section at 5-5 of Figure 1 looking in the direction of the arrows, and

Figure 6 is a broken section at 6-6 of Figure 2 showing more particularly the means for holding the spring collar in place.

The tool of the drawing is a pneumatic hammer and comprises a barrel or cylinder I0 to which is attached a cap or handle section I2. For this purpose the barrel I II is provided with threads I4 cooperating with corresponding threads I6 on the cap portion so that the barrel screws into the handle.

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v(Cl. 287-125) In order to prevent unscrewing of the cap I2 from the cylinder I0, means is provided to engage these two parts which rigidly prevents relative rotation therebetween. To this end a locking ring I8 is provided having jaws 20 which cooperate with complementary jaws 22 formed on the threaded end of the cap I2. Engagement of the jaws 2li and 22 prevents relative rotation of the locking ring I8 with respect to the cap I2. Likewise, in order to prevent rotation of the locking ring I8 with respect to the barrel Ill, internal teeth 24 are provided to engage corresponding teeth 26 formed on the exterior of the barrel to be engaged thereby. The locking ring I8 is slidable longitudinally of the barrel and cap into position engaging teeth 24 and 26 and the jaws 20 and 22.

In accordance with this invention, additional means is provided for maintaining the locking ring I8 in engaged position. To this end is provided a spring adapted to be wedged between the cylinder III and the locking ring I 8, preferably in the form of a collar 28 of resilient material such as steel, which is formed with a slight twist as shown in Figure 3. When wedged into position to engage the locking ring I6, the forward edge 30 of the collar 28 is adapted to abut a shoulder or abutment 32 formed on the exterior surface of the barrel I0 and spaced a substantial distance from the teeth 25. Preferably, the spring collar is formed with a plain cylindrical portion 34 to encircle the locking ring I3 and terminating in a shoulder 36, which is adapted to press against the forward edge of the locking ring. The forward portion of the collar 28 is tapered or conical so as to permit the cylindrical portion 34 and the shoulder 35 to pass over the abutment 32. Inasmuch as the collar 28 is split, it may lbe sprung to permit the forward edge 30 to be passed over the abutment 32.

In practice, the barrel I and the cap I2 are screwed together to a desired tightness and the locking ring I8 is then slipped over the front of the tool and the teeth 26 and 2E are caused to engage at a suitable point at which the jaws 29 and 22 will also engage. For this purpose the number of teeth 24 and 26 is not an exact multiple of the number of jaws 2i] and 22 so that a position for the locking ring I8 can be found which almost exactly coincides with registry of the jaws 20 and 22. A very slight turning of the barrel I0 with respect to the cap I2 will bring the jaws 20 and 22 into registry. The spring collar is then slipped over the end of the hammer and forced over the abutment 32 until the shoulder 36 engages the locking ring I8 at which point the front edge 30 of the collar will engage the abutment. Springing of the entire edge of the collar into engagement of the abutment 32 may be accomplished either by pushing against the shoulder 36 or by insertion of a screw driver in suitable notches 38 in the edges of the collar.

A detent 40 is provided in the cylindrical part 34 of the collar which may engage a notch 42 to prevent turning of the collar.

To remove the locking ring I8, the collar 28 is pried o by means of a screw driver or other suitable instrument inserted between the collar and barrel I0 whereupon the locking ring I8 is Due to the pressure of the spring collar 28 against the ring I 8 substantially al1 vibration and looseness is eliminated from the structure.

I claim:

In a pneumatic tool, the combination of a cylinder having a threaded portion, a cap screwed on the threaded portion, a ring slidable on the cylinder and adapted to engage the cylinder and the cap, an abutment on the cylinder, and a resilient split collar formed with a slight spiral and adapted to be sprung between the abutment and the ring to hold the latter in place, said collar being tapered and having a shoulder to engage the end of the ring, and a cylindrical porreadily slid out of position to permit unscrewing 15 tion tting over said ring.

of the cap l 2 from the barrel I0.

ROY O. ALLEN. 

